The present invention relates to an actuator and in particular to an actuator for operating a relatively minute device such as a chatheter, a manipulator for operating the cell or a manipulator for operating a robot to be used in a narrow space.
An actuator of the kind or a related actuator, which is disclosed in U.S. patent application Ser. No. 07/764,677 (still pending) as a related application of the instant application, includes a main body having an inner space with an opening, a thin film member connected to the main body for closing the inner space, an amount of thermally expansive gas filled in the inner space, a substance for converting the light into the heat which is accommodated in the inner space, and a controller having a device for guiding the light into the inner space.
In the foregoing actuator, upon application of the light into the inner space of the main body, heat at a degree is generated, and the resultant heat brings the gas into expansion. Thus, the thin film is deformed and the resultant deformation is set to be used as a force for driving a specific element.
However, the foregoing deformation which is read as a displacement of the thin film member is too small to be practical use, which results in that the actuator can be used only in the limited fields.